Broiler



Ocf- 6, 1964 v. J. BROLHLLARD 3,151,607-

BROILER Filed April l5, 1959 4 Sheets-Sheet 1 NS s Oct. 6, 1964 V. J. BROUILLARD BROILER 4 Sheets-5h99;c 2

Filed April 15, 195v CCL 6, 1964 v. J. BROUILLARD 3,151,607

BRoIu-:R

Filed April 15, 1959 4 sheetsheet 3 WM5/vm@ WML J Skov/lanen rro/QA/E Oct. 6, 1964 v. J. BROUILLARD BROILER 4 Sheets-sheet 4 Filed April 15, 1959 /M/E/yro/Q 5V H741. J 5h00/Lam www/M7@ firm/@V526 United States Patent O 3,ll,6li7 BRQHJER Vital 3. Brouillard, 914 S. Washington Ave., Crookston, Minn. Apr. l5, i959, Ser. No. 805,609

12 Claims. (Cl. 126-6) This invention relates in general to cooling apparatus and in particular to indoor grills or open hearth broilers. In recent years, indoor open hearth grills for food cooking have become quite popular and the future prospects are that they will become even more popular. Unfortunately, the grills which have been installed up to the present time and which are presently available for installation have numerous disadvantages which seriously impair the value and enjoyment thereof.

One serious disadvantage is that the grills now employed rely almost exclusively on the room air to support the combustion in the grill which results in a negative or backup pressure in the room and a back draft which frequently blows the smoke fumes and vapors back into the room, smoking and smelling up the house and sometirnes causing damage to the house furnishings.

Another disadvantage is that the broilers presently available are either of the open variety which throws an intense amount of heat into the room, frequently at times when this heat is not desired, or the grills are substantially enclosed and must be supplied with heavy insulation or refractory material which substantially increases the cost and weight ofthe grills or broilers.

rl`hereiore, an important object of my invention is an indoor grill or broiler which employs atmospheric or outside air as distinguished from indoor or room air to support the combustion in the fire pit of the broiler and also to prevent the negative or backup pressures wmch might otherwise occur.

Another object is a broiler of the class described in which circulating atmospheric air is employed as the insulating means for the structure enclosing the broiler.

Still another object is a broiler of the class described in which the incoming outdoor air is heated, which heated air may be selectively employed to assist in the lire pit combustion or to assist in heating the room if desired, or may also be discharged into the room in which the broiler is located to eliminate undesirable backup or negative pressures.

Still another object is a broiler of the class described which is especially designed to trap, condense and filter the smoke fumes and vapors emanating from the combustion climber of the roiler in such fashion as to minimize the amount or objectionable grease and odors winch are discharged to the outside atmosphere, which filtering medium is readily adapted to removal and cleaning thereof.

Still another object is a broiler of the class described which features an adjustable door which when the broiler is in use is employed as a baille to assist in forming a fume and smoke trap to channel the smoke fumes and vapors and products or" combustion into the condensation and trap system and which, when the broiler is not in use, serves as a closure for the/condensation and trap system to prevent the odors therefrom from emanating into the surrounding room when the broiler is not in use.

till another object is a broiler of the class described in which the door above described is supplied with transparent, tinted window media of noncombustible mate-V rial to facilitate the viewing of the cooking by the cook or operator with reduced eye strain.

Patented Oct. 6, i964 A further object is a broiler of the class described which features vertically adjustable and removable foodsupporting grills which are easy to clean and remove, which may be used singly or in combination, and which may be swung to the front of the broiler within easy reach of the cook for seasoning, tasting and sampling.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings,- wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FlG. l is a perspective view of the broiler of my invention;

FIG. 2 is a front elevational view in partial broken away section;

FIG. 3 is a side view in vertical section taken along the lines 3 3 of FIG. 2;

FIG. 4 isa side view in vertical section taken on the line 4 4 of FlG. 2;

FIG. 5 is atop plan view thereof;

llG. 6 is an enlarged detail elevational view in partial section or the height adjusting mechanism for the grill;

FlG. 7 is a cross sectional view taken on the line 7-7 of FlG. 6;

FiG. 8 is an enlarged fragmentary front elevational view of the damper mechanism for the combustion chamber;

FIG. 9 is an enlarged detailed side view of the damper mechanism for the combustion chamber; and

LFlG. l0 is a top horizontal sectional view taken on the line ll-ltl or" FIG. 2, showing the grills and the pivotal movements thereof.

Referring to the drawings which show a preferred embodiment of my invention, the open hearth broiler of my invention consists of a cooking chamber it) having a suitable re pit or combustion chamber 11 located in the lower portion thereof, said cooking and combustion chambers being enclosed by a pair of vertical hollow side walls 12, a hollow back wall 13, a hollow bottom 14, a hollow roof 1S having enclosed therein a plurality of heat exchanger and condensation tubes 16, and a hollow upstanding front wall 17 enclosing the combustion chamber only, leaving an opening thereabove for gaining access to the interior of the cooking chamber. The interior of the roof l5' is in direct tlow communication with the hollow interlor'of the vertical side walls l2 which in turn directly communicate with the hollow interior of the bottom 14, the interiorV of the bottom ld in turn directly communicating with the interiorof the back Wall i3 and front wall 17 ofthe broiler.

it should be'understood that in the form shown in the drawings, there is no direct communication between the interior of the roof l5 and the back wall, nor between the side walls and the back wall, all of the circulated air havingto rst pass through the bottom before entering the back wail.

Mounted atop the roof 15 of the broiler are a pair of blowers l and i9 which are driven by a common driving mechanism such as the motor 2Q mounted atop the roof also by means of a motor mounting bracket 20a, one of said blowers i8 serving as an air intake mechanism for drawing outside atmospheric air into the broiler, the other blower i9 serving las an exhaust mechanism to eliminate the indrawn air and products oi combustion and fumes from the broiler to the outside atmosphere, and to alternatively and selected deliver all orV part of the indrawn air into the room which the broiler is located. i i

'back into' 'the cooking chamber.

The intake blower housing is in direct ow communication with the interior ofthe hollow roof of the broiler and is adapted to direct the air thereinto through the air intake opening 21 in the top or outer wall 15b of the roof (as best seen in FIG. 3) so as to cause the fresh incoming air to pass across or around the condensation tubes 16 and become heated thereby and pass directly from the hollow roof into either of the hollow sides of the broiler, the ar- 'rangement being such that the incoming air splits approximately equally into two equal portions so that the flow down either side of the broiler is of substantially equal intensity. The outside air is drawn into the Iintake blower housing and roof of the boiler through suitable ducts such as 22 which may provide direct communication between the intake blowerand the outside air.

The exhaust blower which is also mounted atop the roof is in ow communication with the condensation tubes 16 disposed inside the hollow roof 15, a collection chamber or trap 23 supplied with a filter 24 being disposed in ow communication intermediate the tubes and the eX- haust blower to collect, condense and eliminate the majority of the grease and dust which is removed from the cooking chamber and normally exhausted to the outside atmosphere by means of the exhaust blower. The iilteredV smoke and fumes are discharged from the trap to the exhaust blower through an exhaust port 25, 'provided in the outer panel 15b of the roof. The trap chamber 23 extends substantially the full width of the broiler, and the lter member 24 encloses the ends of all of the tubes 16 so that all of the gases discharged therefrom into the trap must pass through the lter. All this is best seen in FIG. 4. The bottom or inner wall 15a of the hollow roof serves also as the upper interior roof or ceiling of the cooking chamber 10 as best seen in the side views 3 and 4 inclined upwardly from back to front of the broiler so as to form a generally inverted V-shaped exhaust hood indicated generally by 26 in the front upper portion of the cooking chamber for readyrcollection and removal of the products of combustion, smoke and fumes therein.

A plurality of condensation, exhaustion and heat exchange tubes 16 are horizontally disposed in tiers and in spaced apart parallel relationship within thehollow roof, the forward ends of said tubes being preferably of bellshaped coniiguration and slightly inclined to correspond to the angle of inclination of the roof and are in direct flow communication with the inverted V-shaped exhaust hood 26. The other or backward end of these tubes is in direct ow communication with the trap itself. The front and back ends of the tubes 16 are preferably affixed orwelded to common header plates 27 and 28, the tubes and Vheader plates preferably functioning as a single removable and insertable unit to facilitate ycleaning of the tubes and to provide easy access to the trap chamber. It is also important tonote that the tubes are inclined downwardly towards the trap to insure that any grease condensing in the tube interiors will drain direcly into the trap and not It is, of course, understood that the interior of the tubes are sealed olf from the roof interior and do not Vcommunicate, therewith.

The hollow back wall 13 is in direct flow communication with a pair of adjacent independent discharge conduits or ducts 33 and 34 having Va common wall 29 and has a pair of adjacent discharge openings 30 and 31 therein, which openings have a pair of spring tensioned interconnected dampers or cross-mounted damper mechanismV 32 mounted adjacent said openings to control the air flow therethrough.^ne, of said openings 30 communicates directly with the exhaust duct 33`leading to the outside atmosphere and theother opening 31 communicates directly with a register duct 34 which communicates directly with the room to discharge warm air thereinto. The inter- Y connected damper arms 35 and 36 are disposed 90 degrees posed vertically to permit maximum iiow through its opening. Damper operating means such as operating handle 37 are also provided for operating said dampers so that they do not necessarily have to be always disposed vertically or horizontally but both may be disposed at an incline so that there may be a partial flow or air from the hollow back through both-simultaneously to permit a partialrliow of hot air into the room and the remainder to pass through into the exhaust system.

The upper front marginal edge of the broiler is provided with a swingable door 33 having a plurality of transparent windows 39 of non-combustible material, which door is pivotally mounted to the front marginal edge of the roof. In open operation position, as best seen in FIGS. 3 and 4, the door 3S is detach-ably held by suitable latch means 4i) carried by a cross supporting member 41 which spans the width of the broiler and is axed to the side walls 12. In this position the door acts as a baille and serves to define the inverted V-shaped fume and smoke collecting exhaust hood indicated generally by the numenal 26 and assists in directing the smoke and fumes into the tubes 16. In closed non-operating position, as indicated by the dotted position shown in FIG. 3, the door is held against the front header plate 27 by suitable latch means 42 carried by the inner roof panel 15a. ln some instances it is preferable to have the door 38 detachable as well as swingable in order to facilitate the removal of the tubes 16 and header plates therefor. In assuming this closed position, the door 38 encloses and shuts oif communication between the tubes 16 and trap 23 with the cooking chamber and room interior and prevents undesirable odors from emanating therefrom. Y

The combustion area in the form shown comprises a pair of adjacent combustion chambers or re pits (indicated generally by C and C) which mayY be operated simultaneously or singly as desired. Each combustion chamber includes a hearth portion formed by a course of refractory material such as lire brick 43 which lines the bottom and back thereof and is supported by the inner panels 13a and 14a of the hollow back wall and hollow bottom respectively, and by the combustion support members 68 therebelow. Atop each hearth is seated in spaced apart relationship a grate member 44 adapted to support a Yfuel 45 such as charcoal briquets or wood.

The inner panel 17a of the hollow front wall 17 provides the front'closure for the combustion chambers and is provided with a plurality of air admitting apertures 46 therein (as best seen in FGS.V 8 and 9). Each combustion chamber is provided with a sliding damper plate 47 having apertures 48 therein, said plates being slidably mounted on said inner panel 17a and independently operated by means of pivotally mounted damper plate engaging and motivating members 49 which are, inthe form-shown,.manual1y operatedbyV means yof damperv handles 50 carried externally of the broiler on the front face of the outer panel 17b. Theapertures 46 and 48 and their respective cooperating members 17a and 47 are lo- 'be understood that it is within the contemplation of this.

invention to include a damper Vsystem such as that above described on the rear portion of the combustion chambers and communicating either with the hollow bottom and back wall or possibly both. v v

A pair of food-supporting grills 51 are provided, one for use with each combustion chamber. preferably pivotally mounted to enable it Vto Ybe swung into more accessible position.l In the form shown, each grill, asbest seen in-FIG. 6, is provided with a mounting bracket 52 which is rigidly secured to the main support- Y Ving frame or yoke 51a` of the grill, said bracket having rigidly secured thereto anV outwardly extending operating Each 'grill is pl D handle 53 and a downwardly extending pivotally mounted cylindrical supporting member or boss d.

Each grill is supported by a vertically adjustable grill supporting mechanism housed within the hollow front wall i7 and indicated generally by the numeral 55. This supporting mechanism 55 is shown in enlarged detail iu FIG. 6 and includes an elongate, ertically disposed exteriorly threaded, stationary rotatable screw member 56 drivingly engaged with a pair of intermeshed bevel gears 57 and manually motivated by a crank wheel 58 carried outwardly of the broiler on the front face of the front wall 17. The screw member 56 is telescopically and threadedly engaged with a vertically movable, interiorly threaded sleeve member 59 having a cylindrical bore and a rectangular outer periphery, the interior diameter of its bore corresponding to and being slig1 tly greater than the outer diameter of the grid pivot member Sil. The upper end of the sleeve member 59 pivotally but snugly and removably receives and seats the grl pivot member 54, and securely supports the grills thereon to maintain the same in substantially horizontal position above the dre in the combustion chamber. The movable sleeve member 59 is telescopically and slidably enclosed within a stationary, rectangular outer sleeve member 60 which prevents rotation of the movable sleeve member S9 and enables it to move vertically up and down to selectively adjust the height of each of the grills.

As an optional but preferable additional feature of my broiler, an elongate drip pan 61 is provided which overlies the front wall l and extends outwardly therefrom, and is located intermediate the top of the front Wall 17 and the grill. The drip pan is provided with a pair of longitudinally extending depending danges 62 which tit over and engage the outer faces of the front wall to removably maintain the drip pan on the front wall. The drip pan is provided with suitable eut-outs or openings which register with the telescoped members of the grill supporting mechanism and permit the movable sleeve 59 to pass freely therethrough.

As another optional but preferred feature (as seen in FlGS. 3 and l0), l provide an ash receptacle 63 in the hearth portion, which receptacle is seated in a suitable opening in the back corner of the hearth. The receptacle may be of the type that can be lifted bodily out of the opening, or it may be connected at its bottom to an ash removing chute or` the bottom may be removable or openable to permit the ashes to fall freely into some sort of ash removing receptacle.

lt should also be noted that in the embodiment shown, the blowers 1S and i9 are driven by the two speed motor 2o through the medium of a common drive shaft 64, the driving power being transmitted therebetween through the blower sheave 6,5 and motor drive pulley d5 which are drivingly interconnected by a drive belt 67.

ln operation after suitable installation of the boiler in a room, the re is ignited in the fire pit on the grates beneath the grills and the motor is turned on causing the intake and exhaust blowers to operate simultaneously. The intake blower draws in air from the outside atmosphere through the intake conduit and delivers this incon ing air to the hollow roof of the broiler causing it to dow over and around the condenser tubes disposed therein, to become heated thereby, the air flow being split into substantially two equal portions which pass down both hollow sides of the broiler, the two columns of air being reunited in the hollow bottom portion of the broiler beneath the hearth.

The damper means conuolling the air flow from the hollow bottom into the rlre pit are adjusted to the setting desired to admit the amount of warmed air necessary beneath he grate so that a portion of the air enters the hollow bottom therefrom into the nre pit to assist in the combustion of the fuel therein. The remaining air passes directly from the hollow bottom portion into the hollow .back portion of the broiler from which it may be discharged entirely into the room through the room register or eausted entirely back out into the outside atmosphere through the exhaust conduit or it may be divided so that a portion is exhausted to the outside and a portion is directed into the room.

The products of combustion, including smoke, fumes, vapors and the like are drawn upwardly by the forced draft created by the exhaust blower and are collected in the hood area dened by theopen door acting as a bale and the forward header plate, and are then drawn through the condensing and heat exchange tubes into the trap chamber, where the vapors, fumes and the like are liltered by the grease filter and then exhausted to the outside.

During cooking, the grills may be raised or lowered as desired to maintain the desired distance between the food supported thereon and the tire by simply lturning the crank wheel 5S. lf for any reason it is necessary or desirable to have access to the food resting on the back por-tion of the grills, such as to season the food, turn it over or to see how well done it is, the grills may easily be swung horizontally degrees to the side on its pivotal mounting (as best seen in FlG. l0) by applying pressure to the grill handles S3, so that the length of the grill parallels the front of the broiler and presents the contents rthereof in readily available fashion, with the drip pan provided therebelow catching ythe drippings from the grill.

From the foregoing description, the advantages of my invention are readily apparent. rfhe air flow passing through the sides, bottom and back of the broiler serves to adequately insulate the broiler so that no special insulating medium is required, and thereby reducing lthe weight and expense of the broiler. ln addition, the air admitted to the combustion chamber and also admitted into the room serves to eliminate the negative pressure which would normally be formed when the sole source or" supply of oxygen for 'the combustion of the fuel is taken from the room itself and, therefore, eliminates any back draft or any passage of smoke, fumes or vapors into the yroo-ru itself. The indrawn circulated air discharged 'mto the room serves not only to eliminate negative or backup pressures, but also effectively heats the room containing the broiler. The grills are readily adjustable for height and location, and the majority of the noxious grease and soot is removed from the fumes and vapors before discharging them to the outside air, so as not to create a nuisance insofar as the surrounding neighborhood is concerned. The condenser tubes and grease trap are readily removable and accessible for cleaning and may be closed olf when not in use. rlhus, the net effect and result of using the broiler of my invention is a pleasant one with little or no objectionable smoke, grease or vapors lin-ding their way back into the room during use and no rancid, stale, pungent odors emanating Itherefrom when the broiler is not in use.

Although the description of my invention has been directed primarily to use as an open hearth broiler, it is to be understood that my invention includes within its scope other uses, such as simply an exhaust hood for such as burners and noxious gases in laboratories where they are both a problem.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

"h t l claim is:

l. indoor open hearth apparatus comprising hollow wall structure heated by and enclosing a combustion chamber having a Irelatively large access opening therein which remains openand communicates with the room housing said apparatus during use and provides a person access to said chamber during use, duct means providing direct communication between Ysaid hollow wall structure and the outside atmosphere for delivering fresh outside air to said hollow wall structure, .duct means'p-roviding direct communication between said hollow wall structure and the outside atmosphere for conveying said air directly back to said outside atmosphere after said air has passed through said hollow wall structure and has been heated adjacent to said access opening whereby said heated air is substantially immediately short-circuited back into said combustion chamber Ithrough said access opening without signiiicantly disturbing the room air and without signiiicantly increasing the temperature of said room.

4. The apparatus of claim l including tubular heatV exchange means mounted in said hollow wall structure and sealed therefrom, said heat exchange means communicating with said combustion chamber for receiving the gaseous products of combustion therefrom, duct means communicating with said heat exchange means and the outsideV atmosphere for exhausting said gaseous products to the outside atmosphere, said heat exchange means being positioned in the path of travel of the fresh air entering said hollow wall structure and contacted thereby whereby the incoming air is heated and the products of combustion cooled by said contact.

5. The apparatus of claim 4, including grease trap means interposed between said heat exchange means and rsaid last named duct means.

6. rhe apparatus of claim 4, wherein said heat exchange means is mounted in a hollow roof-portion of said chamber and communicates with the upper portion of said chamber adjacent said access opening, and including bafe means dependably mounted on said roof portion adjacent said access opening and movable between a closed position Vin which said baiile means closes said chamber having a relatively large access opening therein which remains Yopen and communicates with the room Yhousing said apparatus during use and provides a person access to said chamber during use, a iire pit located in the bottom portion of said chamber, said structure including side walls, a roof, and a bottom underlying said iire pit, airv intake and exhaust openings in Vsaid wall structure, said openings and said Vwall structure being so arranged that air entering same through said intake Yopening passes through all of said Wall structure to said exhaust opening, first V-duct means providing direct communicationbetween said intake opening and the outside atmosphere for conveying fresh outside air directiy to said Wall structure for cooling said structure and heating said air, second duct means providing direct communication between asid exhaust opening and the outside atmosphere for conveying heated air from said wall strucvture backA to said outside atmosphere, third duct means communicating with the outside atmosphere and said chamber for conveying gaseous products from said cham- V'ber to the outside atmosphere, closable dampered means Vfior admitting heated air from said wall structure unpoiluted by said gaseous products to said room, damper means for admitting heated air from said walltstructure to said tire pit to support combination therein, andV (blower means for eecting a fcrced'draft in'saidrductV means and wall structure.V

,SQ Indoor open Vhearth Yapparatus comprising hollow Vwall structure heatedby and Venclosing a combustion chamber having a relatively large access opening therein which remains open and communicates with the room housing said apparatus during use and provides a person access to said chamber during use, a ire pit located in the bottom portion of said chamber, said wall structureV Y inciuding side walls on opposite sides of said opening,

a back wall opposite said opening, a top wall, and a bottom wall underlying said fire pit, said top wall communicating with both of said side walls, both of said side walls communicating with said bottom wall, and said bottom wail being in iiow communication with said back wall, said back wall having an air exhaust opening therein, said top Wall having an air intake opening therein whereby air entering said hollow wall structure through said intake opening passes successively through said top wall,

Vside walls, bottom wall and back` wall and is discharged through said exhaust opening, said air being heated in the course of its passage through said Wall structure, rst duct means providing direct communication between said intake opening and the outside atmosphere for conveying fresh outside air to said wall structure, second duct means providing direct communication between said exhaust opening and the outside atmosphere for conveying heated air from said wall structure directly back to said outside atmosphere, said back wall having a second opening therein communicating with said room for admitting heated air to said room, damper means for opening and closing said second opening, said bottom wall having an opening therein communicating with said iire pit for admitting' heated air thereto to support` combustion, damper means for said opening in said bottom wall, said top wall having a second opening therein, third duct means communicating with said last named second opening and said second duct means, a third opening in said top wall communicating with said combustion chamber for receiving gaseous products therefrom, fourth duct means mounted in said top Wall and sealed therefrom and communicating with said second and third openings in said top wall whereby gaseous products from said chamber pass successively through said fourth, third and second duct means for discharge to the outside atmosphere, and blower means for creating a forced `draft in said duct means and hollow wall structure.

9. Indoor open hearth apparatus comprising hollow wall structure heated by and enclosing a combustion chamber having a relatively large access opening therein which remains open and communicates with the room vhousing said apparatus during use and provides a person rectly back to said outside atmosphere after said air has passed through said hollow Wall structure and been heated thereby, said duct means and hollow wall structure providing a continuous air conduit system, and means for admit- Y ting a portion of the air in said'system to said room adjacent said access opening whereby the air admitted to Vsaid room substantially immediately passes from its point, vof entry into said room into said combustion chamber fthrough said access opening without materially mixing with and changing the temperature of the other air in said room. V

10. Indoor open hearth apparatus comprising Va combustion chamber having a relatively large access opening therein which remains open and communicates with the room housing said apparatus during use and-provides a person access to said chamber Yduring use, hollow wall structure heated by and substantially completely enclosing said combustion chamber except for said accessopeningsaidV Wall structure including inner walls exposed to and deiininglsaid combustion chamberr and outerwalls exposed to the room housing said apparatus, iirst duct 75 Fmeans providing direct communicationV betweensaid` hollow structure and the outside atmosphere for delivering fresh outside air to said hollow structure, second duct means providing direct communication between said hollow wall structure and the outside atmosphere for conveying the fresh air admitted to said wall structure from said irst duct means directly back to said outside atmosphere after said air has passed through said hollow wall structure and been heated thereby, said wall structure being so arranged and said rst and second duct means being connected thereto in such fashion that air entering said hollow wall structure from said irst duct means passes through all of said hollow structure to said second duct means, third duct means communicating with said second duct means and said combustion chamber for exhausting the gaseous products of combustion from said chamber to the outside atmosphere, closaole dampered means for admitting heated air from said Wall structure unpolluted by said gaseous products to said room, and blower means adapted to create a forced draft in each of said duct means and said hollow wall structure.

11. The apparatus of claim 10, including damper means for admitting heated air from said wall structure to said combustion chamber to support combustion therein.

12. The apparatus of claim 10, wherein said blower means is capable of moving the air through said wall structure at a rate suflicient to remove substantially all of the heat therefrom whereby the moving air substantially completely insulates the outer Walls from the inner walls and maintains the outer walls at safety touchable temperatures during use.

References Cited in the file of this patent UNITED STATES PATENTS Jackson Ian. 18, Wicklin Sept, 13, Amos July 26, Bonsor July 8, Thurston Feb. 12, Srnith Dec. 5, Frederick July 20, Street Dec. 26, Morrill Apr. 7, Miller Oct. 19, Free Sept. 10, Fagan Apr. 1,

tacey et al. July 4, Boisset Ian. 9, Grieve Nov. 5, Schillinger July 26, Stoner Aug. 20, Meagher Feb. 20, Baumgartner Feb. 5, Dupler Apr. 23, Siggelkow July 16, Phares June 17, Nelson et al. Apr. 28, Scharmer May 12,

FOREIGN PATENTS France July 11,

UNITED STATES PATENT oEEICE CERTIFICATE OF CORRECTION Patent Noo 3l5l607 October 6, 1964 Vital J, Brouillard It is hereby certified that error appears in the above numbered patent requiring correction and th at the said Letters Patent should read as corrected below Column 7g line 70g for "combination" read Combustion -g Column Qq line 29,1 for "safety" Signed and sealed this 19th day of January 1965e (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. INDOOR OPEN HEARTH APPARATUS COMPRISING HOLLOW WALL STRUCTURE HEATED BY AND ENCLOSING A COMBUSTION CHAMBER HAVING A RELATIVELY LARGE ACCESS OPENING THEREIN WHICH REMAINS OPEN AND COMMUNICATES WITH THE ROOM HOUSING SAID APPARATUS DURING USE AND PROVIDES A PERSON ACCESS TO SAID CHAMBER DURING USE, DUCT MEANS PROVIDING DIRECT COMMUNICATION BETWEEN SAID HOLLOW WALL STRUCTURE AND THE OUTSIDE ATMOSPHERE FOR DELIVERING FRESH OUTSIDE AIR TO SAID HOLLOW WALL STRUCTURE, DUCT MEANS PRIVIDING DIRECT COMMUNICATION BETWEEN SAID HALLOW WALL STRUCTURE AND THE OUTSIDE ATMOSPHERE FOR CONVEYING SAID AIR DIRECTLY BACK TO SAID OUTSIDE ATMOSPHERE AFTER SAID AIR HAS PASSED THROUGH SAID HOLLOW WALL STRUCTURE AND HAS BEEN HEATED THEREBY, AND DAMPERED MEANS FOR ADMITTING HEATED AIR FROM SAID HOLLOW WALL STRUCTURE TO SAID ROOM. 